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Table 3A External separation distances

Hazard Type 1 in a mounded brick-build building – reduced distances for low-density buildings

Quantity of explosives (kg) Reference zone radius (m) Maximum population count in reference zone Reduced distance to buildings (m) if maximum population count in reference zone not exceeded
0.1 – 100 No reduced distances – use distances in column 5 of Table 3 regardless of density No reduced distances – use distances in column 5 of Table 3 regardless of density No reduced distances – use distances in column 5 of Table 3 regardless of density
100 – 150 257 203 128
150 – 200 278 240 139
200 – 300 322 320 161
300 – 600 No reduced distances – use distances in column 5 of Table 3 regardless of density No reduced distances – use distances in column 5 of Table 3 regardless of density No reduced distances – use distances in column 5 of Table 3 regardless of density
600 – 1 600 408 515 204
1 600 – 1 700 416 540 208
1 700 – 1 800 431 573 215
1 800 – 1 900 444 610 222
1 900 – 2 000 458 648 229
2 000 – 30 000 No reduced distances – use distances in column 5 of Table 3 regardless of density No reduced distances – use distances in column 5 of Table 3 regardless of density No reduced distances – use distances in column 5 of Table 3 regardless of density

Column 1 gives two figures in each row for the quantity of explosives. For example, 25 – 50 kg means more than 25 kg and up to and including 50 kg.
There is no distance requirement for a quantity of explosives less than the minimum figure given in the table.
Where the quantity of explosives under consideration is greater than the maximum given in this table, the distance may be calculated using the appropriate formula .

Using reduced distances
The normal distances applying to buildings are in Table 3.
For certain quantities of explosives stored in buildings in low population density areas, the reduced separation distances in Table 3A may be used if the applicant can confirm that the population count in the reference zone does not exceed the maximum.
If reduced distances are adopted, the applicant should continue to monitor population density to make sure that the reduced distances continue to apply.

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Updated: 2011-10-21